Diaper



Oct. 2, 1951 P. STAMBERGER DIAPER Filed May 5, 1947 FIG. I.

lli?! FIG.4.

FIG. 3).

INVENTOR.

BQUL 5TAMBERGER BY 777ad4, q

ATTORNEYS such as latex,

over the absorbent material. "suggestedto' have this water-proof material per- Patentecl Oct. 2, 1951 UNITED STATES PATENT OFFICE 2,570,011 V DIAPER Paul Stamberger, Stamford, Conn.

Application May 5, 1947,?Serial N 0. 7453352 4 Claims. (Grin- 28.7)

The present invention'relates'to an air-permeable diaper.

U'p to the present diapers have been made to absorb the infants urinary fluid from an absorbent material, such ascotton "fabric and *the like. Such diapershave-the disadvantage o'f'being saturated quickly with the above liquid, whichstrikes through easilyto other wearing apparel. To prevent wearing apparel and bed clothes from becoming wet and "soiled, it has been suggested to use flexible water-proof material, flexible rubberized "fabric, jap 's'ilk,-cellophane. The water-proof part is "used It has *been also forated to allow some circulation of air.

The present invention is based upon thedis- 'covery, that ajgreatly improved diaper can be "produced, 'which will jpreventfwetting through, without substantial'reduction of' air ipermeability and porosity.

One of the primary objects of the present invention is to produce a permanent diaper, which "can be repeatedly-used, cleaned or laundered, without changingthe water resisting property' Another object of the present invention is to make'a disposable diaper ora diaperlining, to be discarded after a single use.

Figure lis a plan view of the device.

' 9 Figures 2 and 3- are perspective views of the device folded and ready to be applied to an infant.

Figure 4 is a perspective view-of the device as applied to an infant.

The diaper, according to the' present invention consists in principle of two .parts 301 :sections.

These partsor sectionsdiffer withirespectlto the .uptake'of .the watery .fiuid. One ;parthas .the

capability of rapidwater adsorption, which .will .be called in .the following absorbing section. The other part-has such a.nature,that the .water or substantiallytretard the circulation of air or the evaporation of water an'dwilllnot cause any -.discomfort or irritation =.on .the infant-s tender :consists in measurement the fabric.

skin, frequently noticeable when watr proof garments a'reused.

According to the present "invention the -im-- =proved air permeable diaper is made of an absorbent part, which *iscapable of being-rapidly saturated with Water, and a section-or part which is resistant to the absorption ofwater, mat least *such a degreepthat it will not wet through during normal use.

The absorbent part can bemade from 'any type of material capable of soaking up liquid and in any convenient-shape orsi'ze.

The retarding section 1 can also be made' from the'same or similar material in any convenient shape or size. To prevent rapid saturation-with urinary fluid, this part must, however,"be treated in a definite mannen' to makethis section water resistant without impairing the porosityand air permeability. Wateror urinary fiuids' of high surface tension will not wet such a treated' surface and will onlyshow 'penetration byiapplia- 1 tion of pressure without absorption by the fibers. rSuch a treated surface will not soak 1 up a "water solution of high surface tension during its use.

= itwillbe, however, easily-vetted by asoap solution, or solutions of low surface tension/conse- :quen'tly iit 'can be easily cleaned or laundered.

The fact, that the surface' wi-ll be 'wetted by. and the material is absorbentfor a. soap solution can :be used to test and-also -to demonstrate,

that the porosity :andpermedbllity of the macteria'l remained substantially unchanged after the treatment.

The porosity andthe size of the pores crane -fretarding section must i be, however, kept with- :in certainlimits. *If the sizeof the-pores isabove such a limit,eve'n if the surface is not w'etted,

water will flow unhindered through. The limit 'forthe size o'fthe-poresalso depends'on the type of treatment performed on thematerial of' the "reta'rding' part and can be determined lay-experiments. Any convenient type of'mea-surement .for permeability,

such as the standard hydro- :ts'tatic' test of the I American -Association of Textilechemist z and colorists can paused. This test of the water level, which 'will force water through the openings oi satisfac'tory results were obtained with a product capable of resisting pressu'resof 5 to.100 mm. Products which resisted over 20 :mm. ipres'sure were found to be most suited =for the. purpose l of this invention. Satisfactory "re- :sults were. obtained with material with 'a porosity over 30%, betterresults were, however obtained :with porosities of i 50% or higher.

. woven or knitted fabric.

- polyamides, glass and the like.

- methyl-silicone chlorides.

It is advantageous to make the absorbing part or section from a material of good absorbing property and porosity and of good wetting property for water. The retarding part or sec- No subtion can either be made from the same material, r

or from material of lesser porosity and absorbing property. When cotton fabric is used, for'ex ample, the retarding section can be a tighter The retarding part can also be made from fibers or yarns which have no tendency to absorb Water, such as fibers from plastic material, as polyvinyl products, Any style or out can be used for this diaper product, as long as the absorbing part or section,which comes in contact with the infants body can be placed over the retarding part in actual use.

For making a permanent diaper woven or knit- .ted cotton fabric, either by itself or in combination with a fabricfrom synthetic nonabsorbing fibers can be used. Instead of cotton'or fabric containing cellulose, fabrics made from proteins,

such as wool can be considered.

For making disposablediapers or diaper linings paper is a suitable material.

Both the permanent type of diaper and the disposable one consist of absorbing and retarding parts. v

To give to the retarding section the propertyessential for the purpose of the present invention, -a porous, fibrous material must be treated either chemically or by physical means with a suitable substance. After this treatment the fibrous material or the surface of the nonabsorbent yarns became water repellent or water resistant without substantial change in the air or vapor permeability.

The, treatment of cellulose containing material will be discussed specially in the following.

. such a treatment is the reaction of cellulose with the halogen derivatives of long chain fatty acids,

such as stearyl thiocyanate, chloride, bromide and the like, resulting in the formation of esters with the hydroxyl radical of the cellulose mole- I cule; Such a product will not be wetted any more by water, will resist absorption, although the pore structure is substantially unchanged. Another =method to obtain satisfactory water resistance for the resistihg'secti0n, is the treatment with alkyl-chloro-silicones, such as methyl or di- These silicone compounds form a water repellent alkyl silicone polymer after deoomposingin. the presence of 4 water. Other silicone derivatives suitable for such a treatment are the tertiary-alkyl-aminosilanes. In general, treatment resulting in permanent water resisting, but porous, surface is satisfactory. The most satisfactory treatment results in products with maximum water resisting property with minimum change in the porosity or pore volumina.

A product treated in the above manner, although retaining its porosity will not absorb Water, if a drop is brought on the surface. Such a treated surface will not be wetted by water, and a drop will not spread out, although it will be wetted and be absorbent in contact with a soap solution.

In making the retarding sections for disposable diapers or for diaper linings a chemical compound can be deposited on the surface of the fibres. After this treatment such a surface will become water repellent. An example for such a treatment is the impregnationof waterabsorbing paper with a soap solution, for example 'ammonium laureate and rendering the lauric acid insoluble by forming a salt with a bior tri-valent metal. Instead of the fatty acid, naphthenic acid can also be used.- The behavior of the surface treated in the above manner will be similar 'to thatof a treated cotton fabric, as already referred to.

The amount of such a water repelling material deposited on the surface, or formed on the surface of the fibers, must be limited to such quantities that no substantial decrease of the porosity shall take place and furthermore no continuous film can form. It is advantageous not to reduce the porosity with more than 10 to of the original porosity.

'into substantially equal parts, the transverse line EE indicating the dividing line between the two sections. Since the sheet requires folding to produce the multi-ply effect, the sheet dimensions are such as to permit the needed folding action to produce the folded assembly as having the dimensions desired for actual service use.

Due to the fact that the absorption section provides the inner ply of the assembly, it is apparent that the folding must take place in a particular regimen to secure this result. Hence, in practice, the sheet is first folded on lines which extend parallel with the longitudinal axis of the sheet, the direction of lines 0-1). The articular distance of these lines from such axis will depend upon the width required for the securing of the diaper in position. Folding on these lines does not disturb the relation of sections A and B relative to each other, the overlying portions being of the same section as the underlying portions. The section A is then folded tooverlie section B to permit positioning of the infant on the absorbent section. The diaper is thenproperly drawn about the infant and pinned as usual.

A disposable diaper or diaper lining, according to the present invention, can also be manufac tured in one plane, whereb the retarding section has to be folded below the absorbent one. Such a diaper can'also be made from laminated material.

The term water resisting or resistant is used in accordance with "the technical literature. Water resistant means: resistant to water and porous to air (see Herbert P. Pearson, Water Proofing of Textile Fabrics, New York 1924, page 8). For the purpose of the present invention material with substantial porosity and with hydrophobic surface properties are suitable. The softness of such a material must not be impaired by treatment.

The air permeable diapers, as described hereby, can be used either by themselves, or with a panty type air permeable garment. Such a garment can bemade from a water resisting cotton fabric, or to facilitate cleaning, from fabrics woven or knitted of water non absorbing yarns, such as nylon or saran yarns. The surface of the latter must be rendered sufliciently water resistant or hydrophobic not to allow any penetration of watery liquids during regular use.

I claim:

1. An infants diaper adapted to be folded upon itself to form a multi-ply formation, said diaper comprising a single-ply sheet of soft, porous, water-absorbing material dimensioned to permit folding to produce a multi-ply formation, said sheet having a predetermined portion of its length treated to render said portion water-repellant with the remaining portion unaffected by the treatment, said treatment being ineffective to materially vary the softness and porosity of the material of the treated portion, said treated portion being .so located that when the diaper is folded for service the water-repellant portion overlies and forms a cover for the absorbent portion.

2. A diaper as in claim 1 characterized in that the sheet is initially of integral fibrous material of soft, porous and water-absorbing characteristic and rendered serviceable for diaper usage by treatment of one of its end zones to render the fibres of substantially half the length of the sheet water-repellant while maintaining the sheet porosity unaffected.

3. A diaper as in claim 1 characterized in that the treated and the absorbent portions of the sheet are of substantially equal-sized dimensions and positioned to divide the sheet length transversely into respective end-sections, regimenfolding of the sheet into service formation serving to position the absorbent section as the inner ply of the formation with the water-repellant section as the outer ply of the formation.

4. A diaper as in claim 3 characterized in that the folding regimen involves an initial folding on a pair of lines parallel with the longitudinal axis of the sheet and intersecting such transverse division between sections to thereby retain the sectional relation of the sheet portions so folded, and then folding such folded sheet on or parallel with the transverse division line separating the sections to position the absorbent section as internal of the water-repellant section.

PAUL STAMBE'RGER.

REFERENCES CITED The following'references are of record in the file of this patent:

UNITED STATES PATENTS 

